On 7/3/25 04:35, Daniel P. Berrangé wrote:
On Thu, Jul 03, 2025 at 06:02:38AM -0400, Andrea Bolognani via Devel wrote:
On Wed, Jul 02, 2025 at 02:01:07PM -0600, Jim Fehlig wrote:
On 7/2/25 10:11, Andrea Bolognani wrote:
On Thu, Jun 26, 2025 at 03:29:58PM -0600, Jim Fehlig via Devel wrote:
However, I do understand this
change could break existing ARM VM configurations containing a SCSI
controller without a model specification. One could also argue the pain
inflicted is tolerable :-).
I don't think this should necessarily be a concern.
Unlike, say, USB controllers, where in some cases you could end up
with no model recorded in the XML, for SCSI controllers we always
either figure out a suitable model or fail defining the domain
altogether.
So changing the default here should have no impact on existing
domains and simply improve things for newly-created ones.
I was thinking of transient domains with no explicit model defined. Prior to
this change they would get lsilogic, afterwards virtio-scsi. In practice I
doubt there are (m)any such domains in existence.
I don't use transient domains so I might be missing something, but my
understanding is that by definition they can't really expect ABI
stability to the extent regular domains can since every creation
event is independent from the previous ones from libvirt's
perspective.
With transient VMs, the mgmt app has to take responsiblility to
query the expanded XML and preserve it, if it needs ABI stability.
Thanks for the clarification. I've pushed the patch.
BTW, what do you think about a similar change for x86_64? I vaguely recall the
choice of lsilogic for broader Windows support. We checked w2k8r2-w2k25 and
win10, none of which contain an LSI Logic driver. virtio-scsi may be a better
default for x86_64 as well.
Regards,
Jim
